Currently, the internet is being utilized as an essential communication media. Information provision and confirmation through the internet have been common and there is a growing tendency for wide use of the internet.
In order to use the internet, a terminal (such as a computer, a PCS phone, a cellular phone, a notebook PC, and a PDA) including a chip or a device capable of making connection with the internet is required. However, each terminal can be connected with the internet in different manners. For example, a computer or a notebook PC is connected with the internet through a wire, while a PCS phone, a cellular phone, or a PDA is connected with the internet based on a wireless communication protocol. If necessary, a computer or notebook PC can be connected with the internet through the wireless communications by connecting a PCS phone therewith.
As for methods of connecting with the internet through the wireless communications, there are a method of connecting with the internet by using an external mobile communication network including a base station, a base station controller, a mobile switching center and the like; a method of connecting with the internet through an outdoor wireless LAN (local area network) by using a wireless LAN card; a method of connecting with the internet through a wireless packet network, and the like.
Among them, the wireless LAN is a data communication network implemented as expansion or substitution of the wired LAN, and employs a method of transmitting and receiving data in the air by using a radio frequency or infrared rays instead of a wire (for example, 10/100 Base). Considering its coverage, capability, security, and the like, a spread spectrum type of wireless LAN that uses ISM (industrial scientific medical) bands (902-928 MHz, 2.4-2.48 GHz, 5.725-5.85 GHz) has been most widely used.
Further, the wireless packet internet network provides internet services in a packet mode by using frequently bands of 900 MHz and 1.8-2 GHz.
Generally, a user of the wired LAN connects with an LAN server through a cable by using a computer or notebook PC when he/she is located indoors and then also connects with an external internet network. In addition, a user of the outdoor wireless LAN network or wireless packet internet network connects with the internet indoors or outdoors through a network comprising an antenna, an access point, a router (or a hub or bridge), and the like by using a notebook PC with a wireless internet connection module or a PDA housed therein.
Meanwhile, the user of the wired LAN pays only fixed fees contracted with a relevant service provider, while the user of the wireless LAN must pay fees in proportion to the number of packets the user has sent and received through the connected internet Furthermore, since the fees for connection with the internet through the wireless LAN are relatively high, the wired LAN is more economical than the wireless LAN on a monthly payment basis.
Therefore, there is a problem in that users of the wireless LAN inevitably take on heavier monetary burdens than users of the wired LAN. Furthermore, there is also another problem in that when using the wireless LAN or a packet module, the quality of information becomes worse and a transmission speed thereof becomes slower than that of the wired LAN.